Lubricants



I Patented June 28, 1938 UNITED STATES PATENT OFFICE LUBRICANTS Carl F.Prutton, Cleveland, Ohio, assignor, by

ignments, to The Lubri-Zol Development orporation, Cleveland,- Ohio, acorporation of Delaware No Drawing. Application December 31, 1934,Serial No. 760,038. Renewed August 12, 1937 1 Claim.

.15 of withstanding considerably greater pressures per unit area, beforesuch film is ruptured, than previously known lubricants, particularlymineral oil when used in its pure state.

This invention relates to the discovery that I certain compounds, amongwhich are included certain compounds covered by the broad class, asdefined in my above identified application, are likewise particularlyuseful in the field of lubrication.

.35" Certain of the compounds to which the present invention relates areparticularly useful as means for imparting extreme pressurecharacteristics to lubricating compositions generally such aslubricating oils; as means to impart certain char- 30 .acteristics tolubricating compositions not ordinarily possessed thereby and also tofunction as primary lubricants either in their pure state or combinedwith other lubricating constituents.

' It is-a principal object of my invention, therefore, to provide, foruse-in the field of lubrication, certain materials having a wide varietyof 1 usage and by the use of which certain results may be obtained whichhave heretofore been impossible. o Other objects of my invention willappear as the description proceeds.

To the accomplishment ofthe foregoing and related ends, said invention,then, consists'of the I features hereinafter fully described, andparticularly pointed out in the claim, the following description settingforth in detail certain embodi- =ments of the invention, these beingillustrative, however, of but a few of the various ways in which theprinciple of the invention -may be.

chloride, between an unsaturated organic compound and an organic ringcompound.

By reference to page 2 of my copending application now Patent No.2,051,744, of August 18, 1936, certain groups of compounds will be found5 which come within the scope of the present invention, namely,thehalogenated, or more specifically, chlorinated homologs (i. e.,compounds carrying alkyl side-chains) of benzene, naphthalene, anddiphenyl, such as halogenated, or more specifically, chlorinatedtoluene, methyl naphthalene, and phenyl toluene,

Catalysts The catalysts, which it is possible to employ in the formationof the products contemplated for use in the lubrication field by thisinvention, may be broadly defined as any catalysts which promotecondensation reactions of the above type; specific examples of suchcatalysts are anhydrous aluminum chloride, anhydrous ferric chloride,and the addition products formed by the reaction of such anhydrouschlorides with olefines such as ethylene; for example, the additionproduct 5 of anhydrous aluminum chloride and ethylene, A1Cl3.C2H4.Generally speaking, the broad class of catalysts capable of being usedare those well known in the art as being substantially the equivalent ofanhydrous aluminum chloride. 30

Unsaturated organic compounds When the unsaturated organic, compound isa hydrocarbon of the olefine type and the ring compound is of thearomatic type, the resultant product is probably in the nature of ahomologof the'aromatic compound i. e., an alkylate'd aromatic compoundand the reaction may be expressed as follows:-

where R and R" are'organic radicles or hydrogen and R is an aromaticradicle.

The di-olefines or other polyoleflnes such as those produced bypolymerization of the olefines, (e. g. butylenes, pentenes, hexenes,etc.) produce similar products of a more complex nature and 5 forcertain purposes are of a preferred type.

Other unsaturated organic compounds are capable of producing products ofthe type contemplated. A preferred'type of unsaturated compound is onecontaining one or more long chain structures such asthe normal alkylgroups which contain more than three carbon atoms and preferably morethan ten; for example, the lauryl, cetyl and melissyl groups. When suchlong chain unsaturated compounds are used, it may be desirable to useAlC13.C2H4 as the catalyst rather than AlCla.

A complex mixture of unsaturated compounds is usually preferred to asingle pure compound, and a preferred source of such compounds is foundin the products of the so-called cracking" process as applied topetroleum products; for example, cracked gasoline, cracked kerosene,cracked paraffine or otherwaxes, cracked heavy oils, etc.

Unsaturated organic compounds other than hydrocarbons may also be usedand may, for some purposes, give improved results. Examples of suchcompounds are the oxygen-bearing unsaturated compounds, such as theunsaturated alcohols, aldehydes, ketones, ethers, acids, esters andsalts; and more specifically, allyl alcohol, acrolein, crotonaldehyde,acrylic acid, crotonic acid, oleic acid, di-allyl ether, di-allylketone, butyl and amyl acrylate, crotonate and oleate, sodium oleate,aluminum oleate.

In addition to the unsaturated compounds above described, certainunsaturated cyclic compounds are also of use, such as cyclo-hexene andits derivatives.

Aromatic compounds The organic ring compounds may be classified asfollows:

45 Table N0. 1

ing benzene, naphthalene, anthracene, and

50 their derivatives; also compounds of the bridged ring type, such asthe terpenes, and related compounds.

- (b) of the class including the cycloparafiilns, cyclo-olefines, etc.Examples of this class are the following:

( 1) Hydrogenation products of benzene (e. g. cyclohexane, cyclohexene,cyclohexadiene).

(2) Hydrogenation products of naphthalene (e. g. decahydronaphthalene,tetrahydronaphthalene, etc.)

(3) Naphthenes, naphthenic acid, etc.

(0) of mixed type such as hydrindene, hy-

dranthracene, etc.

B. Heterogeneous ring type compounds (a) of the aromatic or allied typeincluding pyridine, quinoline, etc, and their derivatives.

(b) other types such as furan, thiophene,

pyrrole, etc. and their derivatives.v

The organic ring compounds which are preferred for my purpose are thoseof the aromatic type (A (a) and B (a) of the table above).

75 These may be further classified as follows:

Table No. 2

I. Hydrocarbons (A) Benzene and its homologs such as toluene,

xylene, cymene.

(B) Polyphenyls such as diphenyl, diphenyl benzene, and homologs of themsuch as phenyl toluene.

(C) Condensed ring hydrocarbons (1) Naphthalene and its homologs, suchas the methyl naphthalenes. (2) Phenanthrene and anthracene and theirhomoglos such as the monoand di-- methyl, the propyl and iso-propyl,substitution products, e. g. retene. (3) Chrysene and picene' and theirhomologs.

(D) Compounds resulting from substitution of aryl groupsin compounds ofClasses (A), (B) and (C), e. g., di-benzyl, di-naphthyl, phenylnaphthalene, the polyphenylmethanes, etc.

(E) Bridged ring hydrocarbons such as the terpenes and related compoundsincluding pinene, campheneand limonene.

II. Heterocyclic compounds (See Table No. 1, under 3(a) and B(b) forexamples) III. Substitution products (othen than homologs) of compoundsof Classes I and II.

(A) Oxygen-bearing substitution products (See Table No. 3 below, forfurther classifification) (B) Halogen-bearing substitution products (C)Other substitution products, such as those resulting from substitutionof the following groups:

Amino, and subsituted amino groups Imino Azo Hydrazo Hydrazine NitrileIsonitrile Mercapto sulphide Polysulphide 'I'hiocyanate IsothiocyanateIV. Derivatives of the compounds included in Classes I, II, and IIIresulting from additon reactions, such as hydrogenation, halogenation,etc.

Examples of such compounds are the hydronaphthalenes, phenylcyclohexane, phenyl cyclohexanol, cyclohexyl phenol.

Attention-is called to the fact that certain of the compounds may belongto more than one class; as, for example, the halogenated phenols whichbelong in Class III (A) and III (B), or the halogenated amino phenols,Class III (A), (B) and (C).

The oxygen-bearing aromatic compounds (Class III (A)) of Table No. 2 areof particular importance, and are, therefore, classified in furtherdetail according to the nature of the attachment of the oxygen to themolecule, viz:

Table N0. 3

I. Directly attached to one or more carbon atoms, as in the case of:(1') Ethers and analogous compounds (2') Compounds containing the EC-OHradicle, such as alcohols and other derivatives of carbinol (includingphernols, cresols, naphthols, etc.)

(3') Compounds containing .the carbonyl (=C=O) radicle, such'asaldehydes, ketones, organic acids, esters and salts of organic acids,thio-acids and esters of thio-acids (4') Compounds in which oxygen formsa part Of the ring structure, e. g., furan and its derivatives,anthraquinone,

etc.

II. Indirectly attached through the means of some other atom, i. e., inthe form of an inorganic radicle, e. g.

Amide Arsenate. Arsenite Chlorate Chlorite Cyanate HydroxylamineHypochlorite Nitrate Nitrite Nitro Nitroso Oxime Perchlorate PhosphatePhosphite Sulphate Sulphite Sulphinicacid Sulphone Sulphonic acidSulphoxide Thio-sulphate Thio-phosphoric The products resulting from thereaction of compounds are, in general, superior to correspondingoxygen-free compounds, probably as a result of the tendency ofoxygen-bearing compounds to be strongly adsorbed on metal surfaces. Itis to be noted that the products of reaction of oxygen-bearingunsaturated compounds with aromatic compounds are to be preferred torthe same reasons.

The products resulting from the .reaction of unsaturated compounds withhalogen-bearing ring compounds, constitute a class which are veryeffective in thin film lubrication, because of their ability to preventsiezing or scoring of bearing surfaces subjected to extreme pressures.Such compounds are most efiective when oxygen is also present in themolecule; as, for example, the

products resulting from the reaction of unsaturated compounds such ascracked kerosene with halogenated oxygen-bearing aromatic compounds suchas chlorinated diphenyl ether, or the chlor aryl phosphates, e. g. thetri-chlorphenyl phosphates.

Inaddition to the halogen-bearing compounds, organic derivatives oi anyof the inorganic oxyacids are also suitablefor obtaining products use-111 in extreme pressure lubrication. Such products may be formed by thereaction either of un saturated aliphatic derivatives of such acids, (e.g. allyl esters of sulphuric and phosphoric acids) with organic ringcompounds, or of aryl derivatives of such acids (e. g. tricresyl phos,phate) with unsaturated compounds.

I be attached to a carbon atom which is part of a benzenoid ringstructure to prevent the corrosive effect resulting from the easierhydrolysis of other halogen compounds to form hydro-halogen acids.However, where very extreme pressures are encountered, it may benecessary to employ more corrosive materials. In the latter case, thehalogen addition products of aromatic compounds are particularly useful,because the degree of reactivity of the combined halogen may be easilycontrolled.

It may be noted that halogen-bearing products may also be obtained byfirst reacting the unsaturated compound with the ring compound, and 1then halogenating. This is usually the preferred method of preparinghalogen-bearing products except when it is desired to have the halogenattached to a benzenoid structure.

It will be noted that the above referred to halogen-bearing compoundsare of the type which contain a substantial amount of halogen.

The classification of the unsaturated com-" .urated compound or as theorganic ring compound in carrying out the reaction in the presence ofaluminum chloride.

The following table gives typical examples of the unsaturated compoundsand of the organic ring compounds which are suitable for use in carryingout the above reaction in the production of compounds suitable for usein the field of lubrication in accordance with this invention.

Table No. 4

Typical unsaturated Typical organic ring compounds compounds Ethylene.Benzene. Propylene. Toluene. lsopropylene. Xylene. n-Butylcnc. Ethylbenzene. Isobutylene Naphthalene. Polymerized butylenes. Ethylnaphthalene. Polymerized pentenes. Anthracene. Polymerized hexenes.Retene. Cracked gasolene. Diphenyl.

Cracked kerosene. Cracked waxes.

Diphenyl ether. Triphenyl phosphate.

Cracked heavy oils. Cracked petroleum.

Tricresyl phosphate. Cyclohcxane.

Phenyl cyclohexane. Hydro-naphthalenes. Chlor-naphthalencs.Chlor-benzenes. Chlor-diphenyl. Cider-diphenyl oxide.

Uses and advantages In addition to the advantages attained by the use ofcertain products contemplated by this invention to increase the filmstrength of lubri-' eating oils or as lubricants possessing high filmstrength, other advantages may be obtained as follows:

The compounds in general resulting from the condensation reaction of thetype considered herein are extremely stable and therefore resistant todecomposition, oxidation and to gum forming or sludge forming reactionsespecially when used as crank case lubricants in internal combustionengines. In general the class of products which contain long chainstructures and/or multiple chain structures when present in liquidsreduce the rate of change of viscosity with the 'temperature and usuallyhave a tendency to prevent precipitation of crystalline or gelatinousmaterials such as waxes on chilling. Lubricants resulting from the use,either pure or mixed with other lubricating oils, of such products,therefore have the advantages of improved viscosity index and loweredpour point.

It-has been found thatacertain of the compounds above described, eitheralone or in combination with other materials such as lubricating oils,-organic oxygen compounds and organic halogen compounds, are capable ofreducing the rate of wear of bearing surfaces, particularly during thinfilm lubrication and especially when one of the bearing surfaces is of aso-called bearing metal type such as babbitt, brass and bronze. Thiseffect may, in some cases, be independent of the property also possessedby some of such materials of reducing frictiomthat is, reducing powerlosses in bearings.

Certain compounds which are particularly suitable for increasing thefilm strength of lubricating oils when added in small amounts, forexample highly chlorinated naphthalene, have the disadvantage of beingrelatively insoluble in mineral oils, particularly at low temperatures.The oil solubility of these materials may be increased by reacting themwith unsaturated compounds as disclosed herein, as for example inreacting hexachlor naphthalene with ethylene to produce poly-ethylchlor-naphthalenes which are completely miscible with minerallubricating oils.

Since the addition of compounds of the class including the aboveenumerated will usually re-' duce the viscosity of the oil base to whichthe same are added, if a large percentage of such compounds are added,there will be a tendency to destroy thick-film lubrication because ofthe reduction in viscosity of the composition. If an excessive quantityof such compounds are added,

all of the lubrication will then be of the thinfilm type and thereforeproduce a decided increase in the total amount of friction developed.

My invention, therefore, contemplates adding to a suitable oil basehalogenated carbon com pounds having a boiling point over 140 degrees C.and in proportions from 1 to 20% of the total composition.

Extremely active compounds may be effective to accomplish the purposesof this invention when present in amounts even less than the abovereferred to minimum amount of 0.10%.

Other modes of applying the principle of the invention may be employedinstead of the one explained, change being made as regards the methodherein disclosed, provided the step or steps stated by the followingclaim or the equivalent of said stated step or steps be employed.

I therefore particularly point out and distinctly claim as my invention:

A lubricating composition containing as a principal lubricatingconstituent a major amount of mineral lubricating oil with theproperties of such composition affecting its use as a lubricant improvedby incorporating therein aminor amount, based on the amount of mineraloil, of a com-,, pound containing a substantial amount of halogen, whichcompound is a halogenated alkylated toluene.

CARL F. PRUTTON.

